0
我正在繪製應用程序，用戶可以在其中創建矩形，一排孔，孔網格和多邊形。現在我可以通過確定觸摸點是否在對象邊界內，在TouchMove動作期間更新對象座標，然後使用更新後的座標重新繪製對象（以及繪製的所有內容）來移動這些對象。 我的下一步是執行旋轉。到目前爲止，我可以獲得一個旋轉角度，在繪製旋轉的對象時使用它來旋轉畫布，然後恢復畫布，以便其他對象不帶角度地繪製。這工作完美。當我嘗試移動/旋轉旋轉的對象時，問題就出現了。我存儲對象旋轉，但我不更新它的存儲座標;因此，當我嘗試確定用戶是否觸摸了旋轉的對象時，它與用戶在屏幕上看到的內容不匹配。 我需要的是能夠修改對象座標或觸摸座標以反映旋轉。有沒有辦法做到這一點？我是否全部錯了？將旋轉角度應用於原點周圍的座標？
下面是我的一些代碼片段：
這決定了圓的電網已被觸摸：
//retrieve touch coordinates. Adjust for matrix transformations
float currX=(event.getX()-matrixValues[2])/matrixValues[0];
float currY=(event.getY()-matrixValues[5])/matrixValues[4];
//... skip other code for snippet
else if(drawObject.getDrawAction()=="array")
{
ArrayList <DrawAction> redrawArray=drawObject.getDrawArray();
if(drawMode=="remove")
{
//determine which hole in grid was touched. "Remove" it
for(int y=0; y<redrawArray.size();y++)
{
DrawAction arrayAction=redrawArray.get(y);
if(currX>(arrayAction.getDrawX()-arrayAction.getDrawRadius()) && currX<(arrayAction.getDrawX()+arrayAction.getDrawRadius()) && currY<(arrayAction.getDrawY()+arrayAction.getDrawRadius()) && currY>(arrayAction.getDrawY()-arrayAction.getDrawRadius()))
{
arrayAction.setRemoved(true);
//add undo object for this action
DrawAction undoRemove= new DrawAction("remove", arrayAction);
undoList.add(undoRemove);
//redraw objects with updated status
redrawObjects(false);
break outerloop;
}
}
}
else
{
//determine all coordinates within the grid. If we are within the grid, then we want to move the whole grid
float holeRadius=redrawArray.get(0).getDrawRadius();
float lowestX=redrawArray.get(0).getDrawX()-holeRadius;
float lowestY=redrawArray.get(0).getDrawY()-holeRadius;
float highestX=redrawArray.get(redrawArray.size()-1).getDrawX()+holeRadius;
float highestY=redrawArray.get(redrawArray.size()-1).getDrawY()+holeRadius;
if(currX>lowestX && currX<highestX && currY>lowestY && currY<highestY)
{
touchObject=drawObject;
//store coordinates for new coordinate calculations
touchedX=currX;
touchedY=currY;
break outerloop;
}
}
}
這個片段是怎麼確定的角度：
touchObject.setRotationAngle((float) getDegreesFromTouchEvent(currX, currY));
touchObject.setRotated(true);
這是返回角度的函數：
//determine rotation from touch event and screen dimensions
private double getDegreesFromTouchEvent(float x, float y){
double delta_x = x - (screenWidth) /2;
double delta_y = (screenHeight) /2 - y;
double radians = Math.atan2(delta_y, delta_x);
return (-1)*Math.toDegrees(radians);
}
這裏的地方我重繪移動/旋轉後的一切：
//redraw everything
for(int x=0; x<undoList.size();x++)
{
//retrieve next object to draw
DrawAction drawObject=undoList.get(x);
//retrieve object's brush width/paint color
this.setBrushSize(drawObject.getBrushWidth());
drawPaint.setColor(drawObject.getPaintColor());
//save state of canvas. This is so we can rotate it, draw, and then rotate back to its original state
drawCanvas.save();
//if this object has been rotated, then we need to rotate the canvas before drawing it
if(drawObject.isRotated())
{
drawCanvas.rotate(drawObject.getRotationAngle(),drawObject.getCenterX(),drawObject.getCenterY());
}
if(drawObject.getDrawAction()=="circle" && !drawObject.isRemoved())
{
drawCanvas.drawCircle(drawObject.getDrawX(), drawObject.getDrawY(), drawObject.getDrawRadius(),drawPaint);
}
if(drawObject.getDrawAction()=="rectangle")
{
if(!drawObject.isRemoved())
{
drawCanvas.drawRect(drawObject.getDrawLeft(), drawObject.getDrawTop(), drawObject.getDrawRight(), drawObject.getDrawBottom(),drawObject.getDrawPaint());
drawCanvas.drawCircle(drawObject.getCenterX(), drawObject.getCenterY(), 2, drawObject.getDrawPaint());
}
}
if(drawObject.getDrawAction()=="text" || drawObject.getDrawAction()=="delay")
{
drawCanvas.drawText(drawObject.getDrawtext(), drawObject.getDrawX(), drawObject.getDrawY(), drawObject.getDrawPaint());
}
if(drawObject.getDrawAction()=="array")
{
ArrayList <DrawAction> redrawArray=drawObject.getDrawArray();
for(int y=0; y<redrawArray.size();y++)
{
DrawAction arrayAction=redrawArray.get(y);
if(!arrayAction.isRemoved())
{
drawCanvas.drawCircle(arrayAction.getDrawX(), arrayAction.getDrawY(), arrayAction.getDrawRadius(),drawPaint);
}
}
}
if(drawObject.getDrawAction()=="path")
{
drawCanvas.drawPath(drawObject.getDrawPath(), drawPaint);
}
//restore canvas to original state
drawCanvas.restore();
}
在這裏看到我的回答http://stackoverflow.com/questions/21633545/android-imageview-scaling-and-translating-問題 – pskink
@pskink感謝您的回覆，但這需要我重新開始。一切都在繪製在SurfaceView畫布上的單個位圖上繪製。這樣做是爲了讓用戶可以平移/縮放具有預定大小的單個位圖。我的用戶的繪圖空間必須比屏幕大，所以這個功能是必不可少的。我也不確定如何繪製動態大小的矩形和路徑。你的例子使用drawables。 –
只需用canvas將canvas.drawBitmap（Bitmap，Matrix，Paint）替換即可。 concat（矩陣），並做你的繪圖... – pskink